Abstract
The genetic variation in wood property and growth of Taiwania (Taiwania cryptomerioides) was investigated at two test sites in the same general location, but one at 1200 m (LK20) and another at 1900 m (LK24). A rangewide sample of 48 open-pollinated families in Taiwan was involved. The test plantations were 16 years old when the wood property data were collected. Traits studied include wood specific gravity, tracheid length, ring width. DBH at ages13, 16, and 22 and height at age 13 were also analyzed. Site environment had a dominant effect on growth and wood density, but showed little interaction with family. The site effect was evident in large between-site differences in means, range of family means, and size of family variance components and heritability estimates. These differences are attributable to the site characteristics of LK24 (high elevation, upper slope near a mountain crest) and an unfavourable local climate. Taiwania is fast growing and produces quality wood, and is also an interesting species from the perspective of evolutionary biology. Protection of its genetic variability should be a priority to be managed. We propose that the existing five progeny tests be protected since these tests well-represent the genetic variability of the species in Taiwan.